Method of treating cotton fabric and product



Patented Nov. 24, 1936 PATENT OFFICE. I

METHOD OF TREATING COTTON FABRIC AND PRODUCT Clarence E. White, Montclair, N. J., assignor to Wm. E. Hooper & Sons Company, Baltimore, Md, a corporation of Maryland No Drawing. Application September 14, 1933, Serial No. 689,433

1 Claim. (01. 8-20) The invention relates to a method of treating cotton fabric to form a film of cellulose covering and lying in the surface of part or all of the strands or fibers and to the fabric including this film of cellulose.

The method of water proofing cotton cloth by treating it with cuprammonium solution, the accepted symbol of which is Clll'NHsH has been well known and quite extensively practiced for many years. form in and near the surface of the cloth or surrounding the exposed strands or fibers, a filament which is the result of the combination of the cuprammonium with the cellulose at and near the surface of the exposed fibers.

The object of the invention is to remove the copper without removing or degrading the quality of the cellulose film. The fabric treated with cuprammonium as described has in the past been treated with acid to remove the copper, but this has the effect of changing the cellulose film Which is left, to hydro-cellulose which is lusterless and further not desirable because it is weak and easily destroyed and almost lacking in tenacity.

In accordance with the practice of the invention, the copper is removed by the treatment of the fabric, which has been first treated with cuprammonium, with a solution of sodium hyposulphitethe symbol of which is Nazszos plus 51 120. This solution is neutral so that it has no efiect on the fiber or cellulose film, but accomplishes a total and complete removal of the This treatment is understood to' copper which enters into the solution and disappears, being, if desired, washed off or otherwise removed.

The exposed fibers of the cotton fabric retain after this treatment a film of transparent colorless cellulose which, in the absence of dye or other coloring matter, leaves the fabric white, or nearly so, and. of pleasing appearance closely resembling linen; and it is of particular importance that the fabric thus treated is nearly or quite waterproof, depending on the texture, also it sheds water and does not absorb it. I have thus described the method and product of my invention, the description being specific and in detail, in order that the method of practicing the invention and the nature of the resulting product may be clearly understood. However, the specific terms herein are used in a descriptive rather than in a limiting sense, the scope of the invention being defined in the claim.

What I claim as new and desire to secure by Letters Patent is: v

The method of treating cotton fiber to form a cellulose coating thereon which consists in first treating it with a solution of cuprammonium, dissolving a portion of the fiber and thus forming a film thereon containing cellulose and a copper compound and then removing the copper compound by treating the fiber with hyposulphite of soda solution.

CLARENCE B. WHITE. 

